Anti-Ulcerative Colitis Effects and Active Ingredients in Ethyl Acetate Extract from Decoction of Sargentodoxa cuneata

Abstract

Ulcerative colitis (UC) is an intractable disease prevalent worldwide. While ethyl acetate extract from decoction of Sargentodoxa cuneata (EAdSc) has potential anti-inflammatory activity, its effects on UC remain unknown. In this study, the constituent compounds discussed in the literature and identified by gas chromatography and mass spectrometry (GC-MS) were collected, and the blood-soluble components of EAdSc were identified by liquid chromatography-mass spectrometry. The network pharmacology analysis and molecular docking analysis were performed to explore the potential underlying mechanism and active ingredients of EAdSc against UC. Furthermore, mice with dextran sulfate sodium (DSS)-induced UC were used to study the therapeutic effects and validate the mechanism of EAdSc against UC. A total of 53 compounds from EAdSc were identified in the literature and by GC-MS, and 22 blood-soluble EAdSc components were recognized. Network pharmacology analysis revealed that multiple inflammatory signaling pathways are involved in EAdSc's anti-UC activity. Furthermore, molecular docking analysis showed that the eleutheroside A, liriodendrin, epicatechin, 2-methoxy-4-vinylphenol, catechin, androsin, coumaroyltyramine, and catechol may be active against UC through the TLR4/NF-κB/NLRP3 pathway. EAdSc reduced the disease activity, macroscopic colon damage, and histological damage indices, as well as inhibiting DSS-induced spleen enlargement and colon shortening. In addition, EAdSc decreased the levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6, and IL-17, as well as the expression of TLR4, NF-κB p65, NLRP3, and Caspase-1 mRNA in colon tissues. These results provide insights into the anti-UC effects and underlying mechanisms of EAdSc and help elucidate the active ingredients of EAdSc in the treatment of UC.

Keywords: Sargentodoxa cuneata; TLR4/NF-κB/NLRP3 pathway; gas chromatography and mass spectrometry; liquid chromatography–mass spectrometry; molecular docking; ulcerative colitis.

Figure 1

Results of the Gene Ontology (GO) enrichment analysis. The (a) biological processes, (b) cellular components, and (c) molecular functions identified in the GO enrichment analysis of intersection targets. The analyses are based on the core targets of EAdSc components and UC.

Figure 2

Results of the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. The core targets of the EAdSc component and UC are labeled in red font in the figure, while the targets within the blue hexagonal boxes are the core targets selected for validation in subsequent animal experiments in this study. The signaling pathways obtained by enrichment are presented as circles.

Figure 3

The direct targets of the ethyl acetate extract from decoction of Sargentodoxa cuneata (EAdSc) action on the NOD-like receptor signaling pathway. The targets are marked in red.

Figure 4

Results of molecular docking analysis of small-molecule compounds found in the ethyl acetate extract from decoction of Sargentodoxa cuneata (EAdSc) with the key proteins (TLR4, NF-κB-p65, NLRP3, ASC, and Caspase-1) of the TLR4/NF-κB/NLRP3 signaling pathway. The darker green color in the heatmap means that the compound has a strong affinity for the target, and the darker red color means that the compound has a weak affinity for the target.

Figure 5

Results showing the anti-ulcerative colitis effects of the ethyl acetate extract from decoction of Sargentodoxa cuneata (EAdSc), including the (a) disease activity index (DAI) on the 10th day, (b) colon macroscopic damage index (CMDI), (c) spleen index, (d) histological damage index (TDI), (e) colon condition of the animals in each group, (f) colon length of the animals in each group, and (g) HE-stained pathological sections of the colons of the animals in each group. The mesalazine group was administered 0.52 g/kg mesalazine by gavage, and the EAdSc groups were dosed by intragastric gavage with 14.63 mg/kg, 29.25 mg/kg, and 58.50 mg/kg EAdSc. Data are presented as means ± SEM. n = 8 except TDI index n = 6, ^# p < 0.05 vs. the control group, ^## p < 0.01 vs. the control group, * p < 0.05 vs. the UC group, ** p < 0.01 vs. the UC group. SEM: standard error of mean.

Figure 6

Ethyl acetate extract from decoction of Sargentodoxa cuneata (EAdSc) decreased the levels of inflammatory factors, including (a) IL-1β, (b) IL-6, (c) TNF-α, and (d) IL-17, in the colon tissues of animals with ulcerative colitis using ELISA analysis. The mesalazine group was administered 0.52 g/kg mesalazine by gavage, and the EAdSc groups were dosed by intragastric gavage with 14.63 mg/kg, 29.25 mg/kg, and 58.50 mg/kg EAdSc. Data are presented as means ± SEM. n = 8, ^## p < 0.01 vs. the control group, * p < 0.05 vs. the UC group, ** p < 0.01 vs. the UC group. SEM: standard error of the mean.

Figure 7

Effects of the ethyl acetate extract from decoction of Sargentodoxa cuneata (EAdSc) on (a) NF-κB p65, (b) NLRP3, (c) TLR4, and (d) Caspase-1 mRNA expressions in colon tissues. The mesalazine group was administered 0.52 g/kg mesalazine by gavage, and the EAdSc groups were dosed by intragastric gavage with 14.63 mg/kg, 29.25 mg/kg, and 58.50 mg/kg EAdSc. Data are presented as means ± SEM. n = 5, ^## p < 0.01 vs. the control group, * p < 0.05 vs. the UC group, ** p < 0.01 vs. the UC group. SEM: standard error of mean.